CONSONANCE PREAMPLIFIER
OWNER’S MANUAL
TABLE OF CONTENTS
Introduction
Initial Inspection
Features
Installation
Input Impedance Adjustments
Preamplifier Internal View
Impedance Adjustment Diagram
Overall Gain Adjustments
Gain Adjustment Diagram
Control Instructions
Remote Operation
Technical Specifications
Introduction
Congratulations on your purchase of what is unquestionably one of the finest analog
preamplifiers available today. With its combination of features such as full function
remote control, balanced outputs and state of the art circuitry, your Consonance
Preamplifier will give you many years of trouble free, top quality performance and
enjoyment.
Please take a few moments to read this owner’s manual. The Consonance offers a large
number of interconnect and user operational possibilities. A thorough understanding of
these features will allow you to gain the maximum performance for which this
preamplifier was designed.
The Consonance Preamplifier’s serial number begins with the letter A and is followed by
a four digit number. The serial number is located on the left side of the back panel. All
correspondence with your dealer or Jeff Rowland Design Group concerning this
preamplifier should include the serial number.
For any additional information or assistance, contact your dealer or the Jeff Rowland
Design Group factory.
Initial Inspection
Inspect the shipping container for damage. If the shipping container or packing material
is damaged, it should be kept until the contents of the container have been checked for
completeness and the preamplifier has been inspected both mechanically and
electrically. This preamplifier was fully tested and carefully inspected before shipment. It
should be free of any exterior defects and in perfect operational order upon receipt.
If there is any damage or defect or if the preamplifier does not operate correctly, notify
your dealer immediately. If the shipping container is damaged or the packing material
shows signs of stress, notify the shipper and Jeff Rowland Design Group. Keep the
shipping material for the shipper’s inspection.
In the shipping box you will find:
• AC power cord
• replacement fuses
• infrared remote control transmitter
• infrared remote control receiver and interconnect cable
• warranty card (This form must be completed and returned to JEFF ROWLAND
DESIGN GROUP [or its authorized distributor if outside the U.S.A.] within 14
days of purchase. Not only will your preamplifier be registered, but you will, in
the future, be notified of possible design updates, improvements and new
products.)
We strongly suggest that you save all packing materials
Features
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Six line inputs, the first of which can be used as an optional phono input
Balanced outputs, in both RCA and XLR connector configurations
Regulated power supply with toroidal transformer
Microprocessor-controlled volume and switching
• A digitally-controlled resistor matrix volume control provides 200 precise, individual
steps
• User-stored level settings for all six inputs allow immediate recall of a "normal" level
for each source
• Dual-rate attenuator adjustment controls provide efficient volume control adjustments
• Fluorescent front panel display indicates operational status of the preamplifier under
all ambient lighting conditions
• User controlled display shut-off
• Infrared remote control of all preamplifier operational functions
• Separate remote receiver permits remote operation of preamplifier from a distant
location
• Image shift control (instead of channel balance trim) maintains overall volume level
while shifting stereo image left or right
• Mono and left or right channel cut functions
• Main outputs are muted temporarily during initial A/C power up, power drop or power
interruption
• All signal amplification utilizes high-current, Class A, solid-state technology
• All inputs and outputs are direct-coupled, thus eliminating the effects of capacitors in
the signal path.
• Independent power supply regulators are located at each stage of each amplifier
channel
• Mil-spec circuit board material, with oxygen-free copper traces and high- temperature
mask, provides superior electrical characteristics and long term protection against
adverse climatic conditions
• All signal switching is accomplished with hermetically sealed, gold-clad silver contact
signal relays
• All critical circuitry is encapsulated in a thermally-conductive epoxy to ensure excellent
thermal stability, mechanical integrity and ease of service
• Ability to drive any length of interconnect cable into a balanced 600 ohm load
• Adjustable input and output impedance minimizes source, load and cable interactions
in any application
Installation
Place the preamplifier as close as possible to its final installation point. If possible, allow
easy access to the back panel for making signal and power connections. The preamplifier
should be placed at a sufficient distance from other audio components such that there
will be no interference from stray electromagnetic fields.
The preamplifier is equipped with a power switch located and identified on the rear
panel. The power switch should be turned on after plugging the A/C power cord into the
A/C mains socket located on the back of the preamp. After turning on the preamplifier,
there will be a two second delay, and then the words "THE CONSONANCE" will be
displayed. Immediately thereafter, the display will indicate either "PHONO EQUIPPED" or
"PHONO DELETED" depending upon whether or not a phono module has been installed
within the preamplifier. The display will then switch to its normal status-indicator format.
Your preamplifier is now fully stable and will accept commands.
The rear panel power switch should be left on at all times, thereby maintaining stable
operating parameters and thereby improving performance, reliability and longevity.
Power consumption in stand-by mode is less than 30 watts, providing low-cost
operation.
Your Consonance is equipped with an infrared remote control receiver box which can be
attached to the back of the preamplifier via the provided 3 meter interconnect if remote
operation is desired. The remote control receiver box may be placed anywhere within
line of sight of the hand-held remote transmitter. A longer remote receiver cable may be
ordered on a custom basis from the factory for special applications.
Inputs 1-6 are normally used as line level inputs. If the preamplifier is equipped with the
phono option, then the input 1 RCA connectors become phono inputs. The phono inputs
on a phono-equipped Consonance cannot be used as line level inputs without incurring
possible damage to the preamplifier phono circuitry. A ground "thumbscrew" is located
near the input 1 connectors for use as a ground connection for phono operation.
Normally, this ground connection would not be used when the Consonance is used
exclusively as a line level preamplifier.
Balanced Main output signals are always produced by the preamplifier circuitry and are
available regardless of any input signal source chosen. Single ended Main output signals
are available at the NORMAL output connectors. Signals inverted by 180 degrees relative
to the NORMAL signal outputs are available at the INVERT output connectors.
The Consonance Preamplifier can be adjusted to facilitate different input and output
impedances and gain structures. These adjustments are located internally and require
the removal of the top cover. They can be performed easily, provided the instructions
located in this manual under the heading "Impedance Matching" and/or "Adjustable
Gain" are followed precisely. If you are in any doubt as to the proper adjustments to be
made, contact your dealer or the factory for assistance.
Phono/Line Input Impedance Adjustments
The Consonance Preamplifier permits you to optimize the input impedance of all inputs.
This will optimize interconnect performance by minimizing source and load interactions.
Impedance for all inputs can be set internally. Some sources cannot be loaded at the
lowest input impedance option available on this preamplifier (300 ohm). In these cases,
the high input impedance option should be selected (50K).
The Consonance Preamplifier is shipped from the factory at a 50K ohm input impedance
and a 300/600 ohm balanced output impedance. If you are unsure as to what input
impedance settings to use, simply leave the switches in the positions set at the factory.
If you desire to adjust the impedances, the preamplifier’s top cover must be removed.
With a number 2 Phillip’s screwdriver, remove the three flat head screws closest to the
top on each side of the preamplifier. Also, remove the one screw located in the center
back top of the top cover. The top cover can now be lifted directly up from the
preamplifier. While facing the front of the preamplifier, locate a light blue switch housing
nearest the TAPE OUT connectors. This is the Line Input Impedance switch. (Please refer
to the diagram on page 7.) Gently slide each white switch to the desired location as
outlined on page 8. Each switch, when moved to the "ON" position, terminates its
respective input with a 300 ohm input impedance. If no switches are selected "ON", then
each input will be terminated with a 50K ohm input impedance. Any or all inputs can be
adjusted in any impedance option desired.
The Consonance Preamplifier also provides options for setting cartridge loading
impedance when using the phono option. Two options are available: twelve switchselectable load impedances or plug-in sockets which allow the installation of any fixed
value resistor. The selectable load impedance switches are located adjacent to the phono
module (please refer to the diagram on page 7 of this manual). To adjust, gently slide
each white switch to the desired location for both switch housings as shown in the phono
cartridge loading diagram on page 8.
If a cartridge loading value is required which is not offered by the twelve switches, then
a resistor can be inserted into the appropriate sockets located between the two cartridge
loading switches described above. This option requires that the loading switches be set
in the 47K ohm position (all off). The phono loading socket consists of two parallel rows
of seven sockets each. For best performance, a 1% metal film 0.25w resistor should be
used. The selected resistor would be installed between these two rows of sockets (i.e.
one end of the resistor in one row and the other end of the resistor in the adjacent
socket in the other row). The three end sockets in each row are the active loading
sockets for each channel and are electrically connected and in parallel. The middle
socket in each row is connected directly to ground and is not used. If additional loading
capacitance is needed, then a suitable capacitor can be installed in the same way. With
no capacitor installed, the input capacitance of the Consonance Preamplifier is
approximately 150pf.
If the preamplifier is not equipped with the phono option and input 1 is configured as a
line input, then a jumper should be installed in the 10-pin phono module socket. If
needed, this jumper is available from the factory at no charge. When the line level
option is chosen, the cartridge loading switches must be set in the 47K ohm position.
The input impedance of input 1 configured as a line input will then be solely defined by
the position of the line input impedance switch as outlined above.
All input impedance switches may be switched during listening if desired.
Preamplifier Internal View
Impedance Adjustment Diagram
Overall Gain Adjustments
The overall gain structure of both the line stage and the phono stage (if phono
equipped) of your Consonance Preamplifier can be configured to one of two different
values. The Consonance can thus be used with a wide variety of analog and digital
sources, since many digital sources such as compact disc players and digital-to-analog
converters have high output voltages relative to tuners, tape decks, etc. In addition, a
phono equipped Consonance can be used with both moving magnet (MM) or moving coil
(MC) phono cartridges. This feature also allows you to tailor the gain structure for use
with power amplifiers of non-standard gain parameters and/or loudspeakers with various
efficiencies.
The gain switches are on the underside of the plug-in modules located in the
preamplifier. The top cover should be removed according to the instructions outlined in
the "Impedance Matching" section of this manual. Once the top cover is removed, the
modules can be lifted directly upward from their sockets. Underneath each module is a
switch similar to those used to set input and output impedance. Adjust these switches
according to the module diagram shown on page 10. After the gain switches have been
set to the desired positions, reinstall the modules, paying careful attention to the exact
alignment of the pins and sockets. If you are in doubt as to this procedure, then contact
your dealer or the factory for assistance. Incorrect installation of these modules may
result in damage to the preamplifier circuitry which cannot be covered under warranty.
With a phono-equipped preamplifier, the 42dB gain option should be selected on the
phono module for use with MM or high output MC cartridges. The 60.2dB gain option
should be selected for use with most MC phono cartridges.
The electrical and sonic performance of the preamplifier will not be compromised by any
gain structure chosen although the higher gain structures are preferred on the line
module as they allow the input circuits to operate at lower levels.
Gain Adjustment Diagram
Control Instructions
The Consonance Preamplifier utilizes a microprocessor to control all functions including
volume level. All control commands can be initiated with both the front panel push
button switches and the remote control keypad. The front panel push button switches
utilize 18 push buttons to implement 21 commands. Certain selected functions are
initiated by pressing two push buttons simultaneously. The hand-held remote
transmitter implements these same selected functions, in addition to all other functions,
with single keypad buttons.
A fluorescent front panel display indicates the status of each function. Each available
function is discussed in detail in this section.
Command Types
Toggle Commands
Toggle functions have two states, active and inactive. Pressing the same push button or
push button sequence will cause the state of the selected function to alternate. Toggle
commands will have "(TOGGLE)" after the command heading.
Continuous Commands
These commands may be entered in one of two ways. The specified function may
require a single push button press which causes a single step response. Or the same
button may be held down (1) to allow the function to continue stepping until the button
is released or (2) until the function’s full range is reached. Continuous commands will
have "(CONTINUOUS)" after the command heading.
Single Commands
Single commands have an effect only the first time they are entered (unless other
commands have been entered since that time). Single commands will have "(SINGLE)"
after the command heading.
Functions
INPUT/RECORD (TOGGLE)
Pressing this push button will display a "<" or ">" symbol on the left end of the display.
This symbol pointing to the left will indicate which input is routed to the preamplifier
Main Outputs for listening. This symbol pointing to the right will indicate which input is
routed to the preamplifier Record Outputs for recording.
Note: If your system utilizes a signal processor or tape recorder, you should use input 6
on the rear panel as the processor or tape input (return). Selecting input 6 when the
INPUT/RECORD button is in record will display a "0" in the front panel display. This
prevents the possibility of causing a feedback situation when a signal processor or tape
deck is connected.
1, 2, 3, 4, 5, 6 (SINGLE)
Pressing any of the numerical push buttons will route the selected input (indicated on
the front panel display) to either the Main Outputs or Record Outputs depending upon
the last command of the INPUT/RECORD button. Any input can be used simultaneously
as an input and record source.
STORE (SINGLE)
Pressing this push button stores the existing volume level of the selected input within
the internal preamplifier memory. Up to six independent levels, one for each input, may
be stored. When activated, the word "Store" is shown on the display for two (2)
seconds. Pressing this button also overrides any previously stored level for the selected
input.
RECALL (TOGGLE)
Pressing this push button will recall the stored volume level (referenced above) in each
selected input. This function will indicate an "R" on the front panel display when
activated. If this function is not activated, then the volume will be controlled by the
VOLUME buttons.
MUTE (TOGGLE)
Pressing this push button removes the signal from the Main Outputs. The last selected
volume levels displayed on the front panel will be bracketed by "< >". Note: When the
volume levels of both channels are displayed as "00" the preamplifier Main Outputs are
also muted.
BALANCE (CONTINUOUS)
Pressing the second or fourth push button in the right group of push buttons initiates a
channel balance or stereo "image shift" function. Pressing the second push button will
shift the stereo image to the left while pressing the fourth push button will shift the
stereo image to the right. Continuous pressure on either button will gradually shift the
stereo image until a maximum differential of 40 steps (approximately 8dB) has been
achieved. Note that as the level of one channel is increased by one volume increment,
the level of the other channel will also be decreased by the same amount, thereby
maintaining the overall stereo volume level.
Either right or left channels can be muted independent of one another by simultaneously
pressing the second and third buttons or the third and fourth buttons respectively. When
a particular channel is cut or muted, the respective volume level indicated on the front
panel display will be replaced by "--". Repeating the same sequence will restore the
channel to its original level.
MONO (TOGGLE) Pressing this push button electrically sums the selected stereo input
signal into a mono signal available at both Left and Right Main Outputs. This function is
active when the character "M" is indicated on the front panel display.
PHASE (TOGGLE)
Pressing the PHASE push button reverses the absolute phase of the preamplifier Main
Outputs relative to the preamplifier Line Inputs.
VOLUME (CONTINUOUS) Pressing the seventh or ninth push button in the right group of
push buttons initiates an incremental volume change of both right and left channels
simultaneously. A total of 200 discrete volume levels are available. Pressing the seventh
button will increment the volume level down in single steps while pressing the ninth
button will increment the volume level up in single steps. Pressing both seventh and
eighth buttons simultaneously will decrease the volume level 10 steps at a time.
Similarly, pressing both the eighth and ninth buttons simultaneously will increase the
volume level 10 steps at a time. Each increment of volume will be indicated by a specific
number on the front panel display. Each increment corresponds to approximately 0.25 to
0.35 dB of volume change above an indicated value of 25. Below the indicated level of
25, the increment amount gradually increases to a maximum of 6dB. The total range of
the volume control is 60dB. The sonic performance or channel tracking accuracy is not
affected by any volume level selected from 1 to 200.
DISPLAY OFF (TOGGLE)
Simultaneously pressing the first and third push buttons in the right group of push
buttons will shut off the front panel display with the exception of four small lighted dots
which will appear in the center. Repeating the same sequence will restore the
preamplifier operational status on the front panel display. Pressing any other push
button when the display is shut off will temporarily restore the display information,
including the four small lighted dots, for five seconds. After five seconds, the display will
return to the off condition.
Remote Operation
The Consonance Preamplifier can be operated from a remote location by connecting the
remote receiver box to the back panel of the preamplifier via the supplied three meter
remote cable. The remote cable can be plugged into either of the two outputs on the
back of the remote receiver box. The spare output connector on the back of this box can
be used to connect another cable to a different remote box in a separate remote
location. You can "daisy-chain" any number of remote receivers at several locations. The
front panel of the remote receiver box should be in "line-of-sight" of the hand-held
remote transmitter signals. A small red lamp located behind the front panel will light
during the presence of the infrared signal. Occasionally, certain ambient lighting
conditions or signals from other hand-held remotes will also light this lamp. Since the
Consonance Preamplifier is only sensitive to the infrared code of the hand-held
transmitter, occasional lighting of this lamp under such circumstances will not normally
interfere with the operation of the Consonance.
If the infrared transmission of other hand-held remotes does interfere with the operation
of the Consonance, two other data rates of infrared transmission can be selected inside
the preamplifier and hand-held remote transmitter. Please refer to the drawing on page
8 for location and position of the switch necessary to select a different data rate. The
switch positions on the back side of the hand-held remote transmitter must match the
switch positions inside the preamplifier.
The hand-held remote transmitter has been designed for a higher infrared output than
average transmitters. Under some conditions, direct "aiming" of the transmitter may not
be necessary since the reflected infrared energy off of the boundaries of a room may be
sufficient for proper remote operation. The remote transmitter can be turned off or
disabled by moving both data- rate switches down on the rear of the transmitter. Normal
use of the transmitter should offer around two years of service on the factory-supplied
batteries. If the batteries need to be replaced, remove the back panel of the transmitter
by taking out the two lower screws on each side of the transmitter case. The transmitter
uses four AAA alkaline dry cell batteries. Please pay careful attention to the proper
polarity of these batteries during installation.
All control commands can be initiated with a single keypad press on the hand-held
transmitter for all 21 available functions. Each command identified on the hand-held
remote is similar to the commands outlined in the Control Instructions section of this
manual with the exception of the following:
Balance commands are one button commands identified by the "L" and "R" on the
transmitter. Pressing the "L" push button will shift the stereo image to the left while
pressing the "R" push button will shift the stereo image to the right.
Pressing either the "L Cut" or "R Cut" push buttons will mute either the left or right
channel respectively.
Volume Pressing the "Vol Down" or the "Vol Up" push buttons changes right and left
channels either down or up respectively.
Pressing the "Vol Dwn Fast" or the "Vol Up Fast" push buttons will change the volume
level down or up by 10 steps at a time.
Display Pressing the "Display" button will shut off the front panel display with the
exception of four small lighted dots which will appear in the center. Pressing the push
button again will restore the preamplifier operational status on the front panel display.
Note: The Roman numeral "II" on your remote control keypad controls the brilliance of
the preamp’s flourescent display. You can choose between four levels of brilliance by
pressing the "II" button four times.
I & III These push buttons will have no effect upon the operational status of the
preamplifier. These push buttons can be programmed for additional functions at a future
date.
Technical Specifications
Consonance Preamplifier
Line Stage Gain
Phono Stage Gain
IHF Input Sensitivity
For 500 MV Output
RIAA Accuracy
Frequency Response:
Phono Line
IHF Signal to Noise (S/N) Ratio,
A Wtd., Ref. 500 MV Phono/Line
THD Distortion, Ref. 2.5 V RMS
Phono/Line
Max Output Level Phono/Line
Dimensions
Weight
Selectable 6/16.4 dB
Selectable 42/60.2 dB
Phono: tape out 0.5 mV or 4.0 mV
Line: main out 75 mV or 210 mV
20 Hz to 50 kHz ± 0.20 dB
0.15 Hz to 220 kHz, -3 dB
0.08 Hz to 200 kHz, -3 dB
77 dB/87 dB
<0.04%/<0.012%
7.5 V RMS/7.5 V RMS
15 0 in. W x 13.75 in. D x 2.65 in H
(38 cm W x 35 cm D x 6.7 cm H)
14 lbs., 6.4 kg